Multiplier on the fly

The following report is applicable the Athlon XP, Athlon XP-M and Sempron

This report is inapplicable to the Laptop as it is because of it which is written towards the motherboard for desktops. It is because processing of the bridge may have bad influence on operation of PowerNow! by the Laptop PC. However, description by my presumption is also included in it. Please confirm it for yourself.

The answer from us to the locked Athlon XP

The starting multiplier of the Athlon XP is fixed.

We recognized that Athlon XP's FID multiplier was Locked after about 39 weeks in 2003.
In these CPUs, it is proved that processing of L3 bridge is invalid.
Furthermore, the multiplier changing function of a motherboard is not useful, either.
But the cause is not clear.
It is very glad that the multiplier of the Mobile Athlon XP-M is not locked.

Please watch the number in a red circle.

About this affair, we recommend you to refer to the following websites.

In order to change the multiplier by such software, it must be recognized as Athlon XP-M.

Required specification

It is required that L5 [2] bridge should be closed. It is the same as mobile CPU exactly. And following one of chip sets should be used for the motherboard.

VIA : The product shipped after KT266A.

SiS : SiS735, SiS740, and SiS748.

ALi : We are not testing. Probably it can do.

ATI : It has succeeded in RADEON 320.

AMD : It seems that it is possible.

The following products are not supported.

nVidia : There is no success report.

About the maximum multiplier

The maximum multiplier which can be changed by such software is the following.
Athlon XP which closed L5 [2] : Since it is decided by L6, it is 11X.
Athlon XP-M : An original rated multiplier.

Changing the maximum multiplier

At last!! ..... We discovered that L5 [1] had an important function.When L5 [1] bridge is closed, L6 bridge becomes invalid and the maximum multiplier is set to 24X.

This displays information with various CPUs by CrystalCPUID.
Although explained later, please watch that "Multiplier / Max" is displayed as 24X in the following pictures.

But since priority is given to this setup of L5 [1] over L6 and it is going to start by 24X in the motherboard which starts in L6 multiplier when mobile CPU is used, cautions are required.

The Core voltage cannot be changed with a general mother board. It is only Laptop PC to be able to change the voltage.

The difference of operation by the BIOS vender.

According to a BIOS vender, it is necessary to consider how the bridge must be changed.

[ Type A ] The products are started by L3 multiplier, even when Mobile CPU is used.

At the Loked Athlon XP, it always starts in a rated multiplier also by the case of Mobile operation.
In these mother boards, it always starts by L3 multiplier or the fixed starting multiplier.
All are solved by closing L5 [1] and L5 [2].
According to our test, the BIOS vender applicable to it is Award.

[ Type B ] The products are started by L6 multiplier , when Mobile CPU is used.

Also by the case of the Loked Athlon, it can start by L6 by making it operate by Mobile.
At these motherboards, when L5 [2] is closed, it starts in L6 multiplier.
Since it is going to start by 24X if you close L5 [1], cautions are required of these products.
With the following products, change of the maximum multiplier is based on processing of the L6 bridge. And we recommend you for L5 [1] to leave as it is.
According to our test, the BIOS vender applicable to it is AMI.

[ Type F ] The product which is not supported

With these products, just as it is going to change a multiplier from software, it freezes. It seems that it is almost impossible.
According to our test, it does not operate in the chip set of the nVidia.

In a surprising thing ..... It is that operation will be continued even if it changes the state of these bridges during operation of CPU. The changes and its reverse changes to Mobile from Desktop are also possible. These were checked by T-Bred1700+ on K7S5A. However, it is thought that it does not operate well depending on BIOS or a vender.

For closing the bridges

It is not necessarily required to scratch the bridge surface.
We thought of "use of a cut end of the bridges."
I filled the laser pit, using conductive paint directly, without scratching the surface of the bridge.
However, when it is not successful, we recommend you to scratch.

Reference, L6 : SFID for Mobile

L6 bridges are not used in CPU of the desktop version. They are all closed and value is 11x.
In the motherboard corresponding to mobile CPU, L6 bridge serves as multiplier rating.
Refer to the L6 bridges for PowerNow!.

Multiplier

ClockFSB133

ClockFSB167

L6[4:0]

Model#

5.0x

667

833

CC:CC

-

5.5x

733

917

CC:C:

-

6.0x

800

1000

CC::C

-

6.5x

867

1083

CC:::

-

7.0x

933

1167

C:CCC

-

7.5x

1000

1250

C:CC:

-

8.0x

1067

1333

C:C:C

-

8.5x

1133

1417

C:C::

-

9.0x

1200

1500

C::CC

-

9.5x

1267

1583

C::C:

-

10.0x

1333

1667

C:::C

-

10.5x

1400

1750

C::::

-

11.0x

1467

1833

CCCCC

All XP's

11.5x

1533

1917

CCCC:

1800FVQ3C

12.0x

1600

2000

CCC:C

1900FLQ3C

12.5x

1667

2083

CCC::

2000FLQ3C

Multiplier

ClockFSB133

ClockFSB167

L6[4:0]

Model#

13.0x

1733

2167

:C:CC

-

13.5x

1800

2250

:C:C:

2400FQQ4C

14.0x

1867

2333

:C::C

2500FQQ4C

21.0x

-

-

:C:::

-

15.0x

2000

2500

::CCC

-

22.0x

-

-

::CC:

-

16.0x

2133

2667

::C:C

-

16.5x

2200

2750

::C::

-

17.0x

2267

2833

:::CC

-

18.0x

2400

3000

:::C:

-

23.0x

-

-

::::C

-

24.0x

-

-

:::::

-

3.0x

400

500

:CCCC

-

19.0x

-

-

:CCC:

-

4.0x

533

667

:CC:C

-

20.0x

-

-

:CC::

-

C = Closed , : = Open

Reference, L8 : SVID for Mobile

L8 bridges are not used for the Athlon of the desktop version. They are all closed.
In the Athlon of the mobile version (or mobile mode), L8 bridgs are the same setup as L11 bridges. Probably they should be used by PowerNow!.

This bridge is used as maximum of SVID recognized by software. The value of this SVID can be changed by software.
But in the usual motherboard, it does not have the hardware which can use it. Therefore, even when SVID is changed, CORE voltage does not change at all.
Of course in Laptop PC, it could be changed.

Appendix : About closing of the bridges for the locked Athlon

When you need processing of the bridges, be careful of below.

How to set the bridge of [Open] to [Close]

We know the Laser pit should be filled with an insulator before anything else.
Then, it is made to [Close] by using electric conductive material.
In the new package(#27648), it might be difficult to connect two points in the bridge.
In this case, it can be solved by filling the laser pit directly with the electric conductive material.

How to set the bridge of [Close] to [Open]

The bridge is set to [Open] by cutting carefully with an edged tool.

L bridges

Method of closing the bridges for the locked Athlon XP

L#

Function

Impedance to GND

Insulation + closing

ClosingDirectly

Notes

L1

It is connected from L3 to BP_FID pin.

Insulated

-

-

Please maintain this state.

L2

Level2 Cache controls

1k Ohm

Non-recommendation(see notes)

It may be invalid in the Locked Athlon.notes : The behavior of the L2 Cache might be not correct.

L3

Start up Multipliers

1k Ohm

Invalid

It is also impossible to use the multiplier change function of the mother board.